Radiotherapy is known which treats a patient by irradiating therapeutic radiation to an affected site (tumor). The radiotherapy apparatus includes an imager system for imaging a transmission image of the patient, a therapeutic radiation irradiating unit for irradiating therapeutic radiation; and a driving unit for driving the therapeutic radiation irradiating unit. The radiotherapy apparatus calculates a location of the affected site in accordance with the transmission images, and drives the therapeutic radiation irradiating unit by controlling a driving unit to irradiate the therapeutic radiation to the location. In such a radiotherapy apparatus, the exposure dose of the therapeutic radiation irradiated to normal cells can be decreased, as compared with the dose of the therapeutic radiation irradiated to the cells of the affected site. In the foregoing radiotherapy, the affected site of the patient is desired to be measured with higher precision.
Japanese Patent Publication (JP 2007-156771A) discloses an image detecting and tracking apparatus that can accurately detect a target from an input image and continuously track it. The image detecting and tracking apparatus includes an image input unit for inputting a video image to acquire an image for each frame; a moving region calculating section that detects a movement region of the images acquired by the image input unit and outputs a detection result as numerical data for each predetermined region of each frame; a pattern detecting and calculating section that detects a pattern of a detection target in the images acquired by the image input unit and outputs the detection result as numerical data for each predetermined region of each frame; a pattern tracking and calculating section that tracks the pattern of the detection target detected by the pattern detecting and calculating section from the image for each frame acquired by the image input unit and outputs the tracking result as numerical data; an existence degree synthesizing section that synthesizes the respective numerical data outputted by the moving region calculating section, the pattern detecting and calculating section and the pattern tracking and calculating section; and a pattern window controller that sequentially calculates an in-frame location of the pattern of the detection target as a pattern window for each frame on the basis of the numerical data synthesized by the existence degree synthesizing section.
Japanese Patent Publication (JP 2005-236508A) discloses an automatic tracking apparatus that can carry out stable tracking without any stop of the tracking when a target such as an invader in an image is tracked. The automatic tracking apparatus inputs images picked up by an imaging unit and tracks the target in the images. The automatic tracking apparatus includes a template matching unit for carrying out a correlation operation between a template image indicating a feature of the target and the inputted image; a shape change detecting section for detecting the shape change of the target; and a template holding control unit for controlling an update algorism of the template image on the basis of the processed result by the shape change detecting section.
Japanese Patent No. 4,126,318 discloses a radiotherapy apparatus control apparatus for detecting a predetermined target site of a specimen with higher precision. The radiotherapy apparatus control apparatus is for controlling a radiotherapy apparatus, which includes a therapeutic radiation irradiating unit for irradiating a therapeutic radiation; an imager for generating images of the specimen from the radiation transmitted through the specimen; a feature site extracting section that generates a plurality of projection templates each indicating changes in projection brightness when a plurality of image templates having different location relation of a target site of the specimen and a non-target site of the specimen are projected in one direction, and generates a feature site template indicating a portion common to the plurality of projection templates; and an affected site location calculating section that performs pattern matching of the feature site template with the changes in the projection brightness when the images are projected in one direction to calculate the location of the target site.
Japanese Patent No. 3,785,136 discloses a radiotherapy apparatus in which a treatment plan can be scheduled easily after the radiotherapy is performed on a specimen. The radiotherapy apparatus includes a radiation irradiating head that irradiates therapeutic radiation; an image processing unit that generates images of the affected site of the specimen to which the therapeutic radiation is irradiated from the radiation irradiating head; and a controller that controls the radiation irradiating head and the image processing unit to repeat a period that includes periods for the generation of the image and the irradiation of the therapeutic radiation, and to generate the image of the affected site after ending the imaging of the image in which prior to the irradiation of the therapeutic radiation in a first period, a diagnostic X-ray is used in a second period following the first period, and after ending a process of the image during the irradiation of the therapeutic radiation in the first period.